The invention relates to a speed-regulated positioning drive for driving a driven shaft of a machine, such as a sewing machine, according to a predetermined program, with a control arrangement and a shaft position indicator which supplies to the control arrangement synchronizing signals synchronized with the rotation of the shaft.
Such drives are employed in a great variety of applications, for example for the driving of machine tools, coil- and condensor-winding machines or presses, and the like. Such drives have also found use in conjuction with industrial sewing machines. The invention is accordingly explained with respect to an industrial sewing machine, although it is not to be considered necessarily limited thereto.
In the sewing machine art, as in many other branches of manufacturing, there is a long-existing trend to automate to the extent possible all operations which have previously been manually controlled or performed, in order to decrease labor costs and increase production.